PD code yields two different knot diagrams

Click For Summary

Discussion Overview

The discussion revolves around the interpretation of a particular PD code, specifically [(2, 3, 1, 4), (4, 1, 3, 2)], and its mapping to knot diagrams. Participants explore the implications of this code in relation to knot theory, particularly focusing on whether it yields a unique knot diagram or multiple representations, including links.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant asserts that the PD code maps to a non-unique knot diagram, presenting two Hopf links with different orientations as examples.
  • Another participant questions whether the diagrams in question are indeed knots, suggesting they resemble interconnected rings instead.
  • A third participant clarifies that the PD code corresponds to a unique link diagram, stating that the Hopf link is valid and noting that a ring is considered the unknot.
  • One participant offers a suggestion to manipulate one of the rings to potentially clarify the situation.

Areas of Agreement / Disagreement

Participants express differing views on whether the PD code leads to a unique knot diagram or multiple representations. There is no consensus on the nature of the diagrams as knots or links.

Contextual Notes

There are unresolved assumptions regarding the definitions of knots and links, as well as the implications of the PD code in this context.

sophiatev
Messages
39
Reaction score
5
TL;DR
The same PD code seems to yield two different knot diagrams of the Hopf link
The PD code [(2, 3, 1, 4), (4, 1, 3, 2)] seems to map to a non-unique knot diagram. I can describe the following two Hopf links with different orientations with this same PD code. As I understand it, while a link diagram does not have a unique PD code, a given PD code should map to just one knot diagram. Am I missing something?

IMG-6314.jpg
 
Physics news on Phys.org
Sorry, the PD code maps to a unique *link* diagram, so the Hopf link is a valid diagram (also, a ring is the unknot so it's still a knot, right? The Hopf link is just two linked unknots)
 
I don't know if it helps, but:

Make half a turn (the least complicated direction) of one of the 4 rings around the horizontal axis.
 

Similar threads

Replies
1
Views
4K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 39 ·
2
Replies
39
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K